This invention relates generally to trailer construction and more particularly to an improved and novel construction for maximizing interior trailer width while maintaining desired structural strength of the trailer sidewalls.
Today, many trailers and other such containers or constructions utilize rectangular panels to form the sides thereof. Heretofore, such trailer bodies have been proposed with various constructions generally including a base frame, and sidewalls having relatively thin sheet material panels fixed to portions of the base frame with closely spaced fasteners such as rivets. Generally, the relatively thin sidewall panel members are joined and/or stiffened by the addition of a number of relatively thick vertical frame members or stiffening members coupled thereto and spaced apart over the length thereof. Such stiffening members often taken the form of sheet metal members which are formed by bending or extrusion into generally U-shaped rib members having extending marginal flanges for coupling to the sidewall panels.
However, regulations governing over the road vehicles, as well as practical considerations in some container applications, generally limit the overall width of the trailer or other container or cargo carrying structure. With such width restrictions, it will be appreciated that the overall effective thickness of the combined sidewall panels and stiffener and/or joining members or ribs applied thereto detracts from the interior width of the trailer or other container. In many instances, standardized sub-containers or pallets for various cargos are sized such that but a single palletized load may be accommodated across the width of a trailer or container of the above-described prior art construction. However, in many instances but an additional inch or even less of interior width would permit two such standardized containerized or palletized loads to be placed side-by-side within the trailer or container.
As an additional matter, we have observed that some downward bowing or concavity of the floor portion of prior art trailer constructions often occurs in response to the loading thereof. Accordingly, as the load in the trailer increases in height, an increased gap is observed between the trailer sidewall and the upper portion of the load, even though the lower portion of the load is positioned so as to abut the sidewall. This downward bowing of the floor leads to such tilting of the load which may detract sufficiently from the available interior width of the trailer as to make the side-by-side loading of a second load of similar width difficult or impossible. This is particularly disadvantageous in the case of the above-mentioned palletized or containerized loads.
At least one prior art attempt has been made to decrease the effective thickness of the sidewall members by eliminating the joining and strengthening frame or rib members. This construction depends upon the strength and rigidity afforded by utilizing a single, relatively thick aluminum panel to form the sidewall of the trailer. However, it should be recognized that a typical such trailer is on the order of 47 feet in length and 112 inches in height. The width of aluminum plate utilized for sufficient rigidity must be at least on the order of 1/4-inch. The fabrication of a 1/4-inch thick aluminum plate in a single piece of on the order of 47 feet in length and 112 inches in height is extremely difficult and expensive, thus adding greatly to the expense of a completed trailer or container which must utilize two such panels for the sidewalls thereof. Moreover, the fabrication of a trailer with such large sidewall panels also can prove difficult and expensive both in handling as well as in achieving proper alignment and fastening of such panels with respect to other structural members of the trailer construction.